84231645521 has 2 divisors, whose sum is σ = 84231645522. Its totient is φ = 84231645520.

The previous prime is 84231645503. The next prime is 84231645523. The reversal of 84231645521 is 12554613248.

It is a strong prime.

It can be written as a sum of positive squares in only one way, i.e., 67410852496 + 16820793025 = 259636^2 + 129695^2 .

It is a cyclic number.

It is a de Polignac number, because none of the positive numbers 2^k-84231645521 is a prime.

It is a super-2 number, since 2×84231645521² (a number of 23 digits) contains 22 as substring.

Together with 84231645523, it forms a pair of twin primes.

It is a Chen prime.

It is not a weakly prime, because it can be changed into another prime (84231645523) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 42115822760 + 42115822761.

It is an arithmetic number, because the mean of its divisors is an integer number (42115822761).

Almost surely, 2^84231645521 is an apocalyptic number.

It is an amenable number.

84231645521 is a deficient number, since it is larger than the sum of its proper divisors (1).

84231645521 is an equidigital number, since it uses as much as digits as its factorization.

84231645521 is an evil number, because the sum of its binary digits is even.

The product of its digits is 230400, while the sum is 41.

The spelling of 84231645521 in words is "eighty-four billion, two hundred thirty-one million, six hundred forty-five thousand, five hundred twenty-one".